aboutsummaryrefslogtreecommitdiffhomepage
path: root/src/video_core/host1x/codecs/vp9.h
blob: f1ed195081574b3d3052e39d5e5175cec4202f42 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
// SPDX-FileCopyrightText: Copyright 2020 yuzu Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later

#pragma once

#include <array>
#include <span>
#include <vector>

#include "common/common_types.h"
#include "common/scratch_buffer.h"
#include "common/stream.h"
#include "video_core/host1x/codecs/vp9_types.h"
#include "video_core/host1x/nvdec_common.h"

namespace Tegra {

namespace Host1x {
class Host1x;
} // namespace Host1x

namespace Decoder {

/// The VpxRangeEncoder, and VpxBitStreamWriter classes are used to compose the
/// VP9 header bitstreams.

class VpxRangeEncoder {
public:
    VpxRangeEncoder();
    ~VpxRangeEncoder();

    VpxRangeEncoder(const VpxRangeEncoder&) = delete;
    VpxRangeEncoder& operator=(const VpxRangeEncoder&) = delete;

    VpxRangeEncoder(VpxRangeEncoder&&) = default;
    VpxRangeEncoder& operator=(VpxRangeEncoder&&) = default;

    /// Writes the rightmost value_size bits from value into the stream
    void Write(s32 value, s32 value_size);

    /// Writes a single bit with half probability
    void Write(bool bit);

    /// Writes a bit to the base_stream encoded with probability
    void Write(bool bit, s32 probability);

    /// Signal the end of the bitstream
    void End();

    [[nodiscard]] std::vector<u8>& GetBuffer() {
        return base_stream.GetBuffer();
    }

    [[nodiscard]] const std::vector<u8>& GetBuffer() const {
        return base_stream.GetBuffer();
    }

private:
    u8 PeekByte();
    Common::Stream base_stream{};
    u32 low_value{};
    u32 range{0xff};
    s32 count{-24};
    s32 half_probability{128};
};

class VpxBitStreamWriter {
public:
    VpxBitStreamWriter();
    ~VpxBitStreamWriter();

    VpxBitStreamWriter(const VpxBitStreamWriter&) = delete;
    VpxBitStreamWriter& operator=(const VpxBitStreamWriter&) = delete;

    VpxBitStreamWriter(VpxBitStreamWriter&&) = default;
    VpxBitStreamWriter& operator=(VpxBitStreamWriter&&) = default;

    /// Write an unsigned integer value
    void WriteU(u32 value, u32 value_size);

    /// Write a signed integer value
    void WriteS(s32 value, u32 value_size);

    /// Based on 6.2.10 of VP9 Spec, writes a delta coded value
    void WriteDeltaQ(u32 value);

    /// Write a single bit.
    void WriteBit(bool state);

    /// Pushes current buffer into buffer_array, resets buffer
    void Flush();

    /// Returns byte_array
    [[nodiscard]] std::vector<u8>& GetByteArray();

    /// Returns const byte_array
    [[nodiscard]] const std::vector<u8>& GetByteArray() const;

private:
    /// Write bit_count bits from value into buffer
    void WriteBits(u32 value, u32 bit_count);

    /// Gets next available position in buffer, invokes Flush() if buffer is full
    s32 GetFreeBufferBits();

    s32 buffer_size{8};

    s32 buffer{};
    s32 buffer_pos{};
    std::vector<u8> byte_array;
};

class VP9 {
public:
    explicit VP9(Host1x::Host1x& host1x);
    ~VP9();

    VP9(const VP9&) = delete;
    VP9& operator=(const VP9&) = delete;

    VP9(VP9&&) = default;
    VP9& operator=(VP9&&) = delete;

    /// Composes the VP9 frame from the GPU state information.
    /// Based on the official VP9 spec documentation
    void ComposeFrame(const Host1x::NvdecCommon::NvdecRegisters& state);

    /// Returns true if the most recent frame was a hidden frame.
    [[nodiscard]] bool WasFrameHidden() const {
        return !current_frame_info.show_frame;
    }

    /// Returns a const span to the composed frame data.
    [[nodiscard]] std::span<const u8> GetFrameBytes() const {
        return frame;
    }

private:
    /// Generates compressed header probability updates in the bitstream writer
    template <typename T, std::size_t N>
    void WriteProbabilityUpdate(VpxRangeEncoder& writer, const std::array<T, N>& new_prob,
                                const std::array<T, N>& old_prob);

    /// Generates compressed header probability updates in the bitstream writer
    /// If probs are not equal, WriteProbabilityDelta is invoked
    void WriteProbabilityUpdate(VpxRangeEncoder& writer, u8 new_prob, u8 old_prob);

    /// Generates compressed header probability deltas in the bitstream writer
    void WriteProbabilityDelta(VpxRangeEncoder& writer, u8 new_prob, u8 old_prob);

    /// Inverse of 6.3.4 Decode term subexp
    void EncodeTermSubExp(VpxRangeEncoder& writer, s32 value);

    /// Writes if the value is less than the test value
    bool WriteLessThan(VpxRangeEncoder& writer, s32 value, s32 test);

    /// Writes probability updates for the Coef probabilities
    void WriteCoefProbabilityUpdate(VpxRangeEncoder& writer, s32 tx_mode,
                                    const std::array<u8, 1728>& new_prob,
                                    const std::array<u8, 1728>& old_prob);

    /// Write probabilities for 4-byte aligned structures
    template <typename T, std::size_t N>
    void WriteProbabilityUpdateAligned4(VpxRangeEncoder& writer, const std::array<T, N>& new_prob,
                                        const std::array<T, N>& old_prob);

    /// Write motion vector probability updates. 6.3.17 in the spec
    void WriteMvProbabilityUpdate(VpxRangeEncoder& writer, u8 new_prob, u8 old_prob);

    /// Returns VP9 information from NVDEC provided offset and size
    [[nodiscard]] Vp9PictureInfo GetVp9PictureInfo(
        const Host1x::NvdecCommon::NvdecRegisters& state);

    /// Read and convert NVDEC provided entropy probs to Vp9EntropyProbs struct
    void InsertEntropy(u64 offset, Vp9EntropyProbs& dst);

    /// Returns frame to be decoded after buffering
    [[nodiscard]] Vp9FrameContainer GetCurrentFrame(
        const Host1x::NvdecCommon::NvdecRegisters& state);

    /// Use NVDEC providied information to compose the headers for the current frame
    [[nodiscard]] std::vector<u8> ComposeCompressedHeader();
    [[nodiscard]] VpxBitStreamWriter ComposeUncompressedHeader();

    Host1x::Host1x& host1x;
    Common::ScratchBuffer<u8> frame;

    std::array<s8, 4> loop_filter_ref_deltas{};
    std::array<s8, 2> loop_filter_mode_deltas{};

    Vp9FrameContainer next_frame{};
    std::array<Vp9EntropyProbs, 4> frame_ctxs{};
    bool swap_ref_indices{};

    Vp9PictureInfo current_frame_info{};
    Vp9EntropyProbs prev_frame_probs{};
};

} // namespace Decoder
} // namespace Tegra